forked from OSchip/llvm-project
f84bc3793e
Summary: Previously, a extending load was represented at (G_*EXT (G_LOAD x)). This had a few drawbacks: * G_LOAD had to be legal for all sizes you could extend from, even if registers didn't naturally hold those sizes. * All sizes you could extend from had to be allocatable just in case the extend went missing (e.g. by optimization). * At minimum, G_*EXT and G_TRUNC had to be legal for these sizes. As we improve optimization of extends and truncates, this legality requirement would spread without considerable care w.r.t when certain combines were permitted. * The SelectionDAG importer required some ugly and fragile pattern rewriting to translate patterns into this style. This patch changes the representation to: * (G_[SZ]EXTLOAD x) * (G_LOAD x) any-extends when MMO.getSize() * 8 < ResultTy.getSizeInBits() which resolves these issues by allowing targets to work entirely in their native register sizes, and by having a more direct translation from SelectionDAG patterns. Each extending load can be lowered by the legalizer into separate extends and loads, however a target that supports s1 will need the any-extending load to extend to at least s8 since LLVM does not represent memory accesses smaller than 8 bit. The legalizer can widenScalar G_LOAD into an any-extending load but sign/zero-extending loads need help from something else like a combiner pass. A follow-up patch that adds combiner helpers for for this will follow. The new representation requires that the MMO correctly reflect the memory access so this has been corrected in a couple tests. I've also moved the extending loads to their own tests since they are (mostly) separate opcodes now. Additionally, the re-write appears to have invalidated two tests from select-with-no-legality-check.mir since the matcher table no longer contains loads that result in s1's and they aren't legal in AArch64 anymore. Depends on D45540 Reviewers: ab, aditya_nandakumar, bogner, rtereshin, volkan, rovka, javed.absar Reviewed By: rtereshin Subscribers: javed.absar, llvm-commits, kristof.beyls Differential Revision: https://reviews.llvm.org/D45541 llvm-svn: 331601 |
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| .. | ||
| 2003-08-03-PassCode.td | ||
| 2006-09-18-LargeInt.td | ||
| 2010-03-24-PrematureDefaults.td | ||
| AllowDuplicateRegisterNames.td | ||
| AnonDefinitionOnDemand.td | ||
| AsmPredicateCondsEmission.td | ||
| AsmVariant.td | ||
| BitOffsetDecoder.td | ||
| BitsInit.td | ||
| BitsInitOverflow.td | ||
| CStyleComment.td | ||
| ClassInstanceValue.td | ||
| ConcatenatedSubregs.td | ||
| Dag.td | ||
| DefmInherit.td | ||
| DefmInsideMultiClass.td | ||
| DuplicateFieldValues.td | ||
| FieldAccess.td | ||
| ForeachList.td | ||
| ForeachLoop.td | ||
| ForwardRef.td | ||
| GeneralList.td | ||
| GlobalISelEmitter.td | ||
| HwModeSelect.td | ||
| Include.inc | ||
| Include.td | ||
| IntBitInit.td | ||
| LazyChange.td | ||
| LetInsideMultiClasses.td | ||
| ListArgs.td | ||
| ListArgsSimple.td | ||
| ListConversion.td | ||
| ListManip.td | ||
| ListOfList.td | ||
| ListSlices.td | ||
| LoLoL.td | ||
| MultiClass-defm-fail.td | ||
| MultiClass-defm.td | ||
| MultiClass.td | ||
| MultiClassDefName.td | ||
| MultiClassInherit.td | ||
| MultiPat.td | ||
| NestedForeach.td | ||
| Paste.td | ||
| RegisterBankEmitter.td | ||
| RegisterEncoder.td | ||
| RelTest.td | ||
| SetTheory.td | ||
| SiblingForeach.td | ||
| Slice.td | ||
| String.td | ||
| SuperSubclassSameName.td | ||
| TargetInstrInfo.td | ||
| TargetInstrSpec.td | ||
| TemplateArgRename.td | ||
| Tree.td | ||
| TreeNames.td | ||
| TwoLevelName.td | ||
| UnsetBitInit.td | ||
| UnterminatedComment.td | ||
| ValidIdentifiers.td | ||
| arithmetic.td | ||
| cast-list-initializer.td | ||
| cast-typeerror.td | ||
| cast.td | ||
| code.td | ||
| compare.td | ||
| dag-functional.td | ||
| defmclass.td | ||
| defset-typeerror.td | ||
| defset.td | ||
| eq.td | ||
| eqbit.td | ||
| foldl.td | ||
| foreach-eval.td | ||
| foreach-leak.td | ||
| foreach-multiclass.td | ||
| foreach.td | ||
| if-empty-list-arg.td | ||
| if-type.td | ||
| if.td | ||
| ifbit.td | ||
| intrinsic-long-name.td | ||
| intrinsic-struct.td | ||
| intrinsic-varargs.td | ||
| isa.td | ||
| lisp.td | ||
| list-element-bitref.td | ||
| listconcat.td | ||
| lit.local.cfg | ||
| math.td | ||
| name-resolution-consistency.td | ||
| nested-comment.td | ||
| pr8330.td | ||
| searchabletables-intrinsic.td | ||
| self-reference-recursion.td | ||
| self-reference-typeerror.td | ||
| self-reference.td | ||
| size.td | ||
| strconcat.td | ||
| subst.td | ||
| subst2.td | ||
| template-arg-dependency.td | ||
| trydecode-emission.td | ||
| trydecode-emission2.td | ||
| trydecode-emission3.td | ||
| usevalname.td | ||